Media player, saving the cache to a memory card - where to dig?

Question

Android

I need to save the files that the media player plays in the cache to a folder. There are no problems with simple sound files. There is a program and a class that does this. And it does it in a strange way, but it works.
Big problems with video files.
Firstly, I wanted to take the easy route and use the mega item ExoPlayer from Goodl. But it does not play my file and apparently many others
https://github.com/google/ExoPlayer/issues/19
Secondly, I tried to make my streaming to a folder in the same way as music. Here is my code:
This class starts the download:

/**  
     * Download the url stream to a temporary location and then call the setDataSource  
     * for that local file
     */  
    public void downloadAudioIncrement(String mediaUrl) throws IOException {
    	URLConnection cn = new URL(mediaUrl).openConnection();   
    	path=mediaUrl;
        cn.connect();
        sizef=cn.getContentLength();
        InputStream stream = cn.getInputStream();
        if (stream == null) {
        	Log.e(getClass().getName(), "Unable to create InputStream for mediaUrl:" + mediaUrl);
        }
        
    downloadingMediaFile = new File(mContext.getCacheDir(),"downloadingMedia.dat");
    
    // Just in case a prior deletion failed because our code crashed or something, we also delete any previously 
    // downloaded file to ensure we start fresh.  If you use this code, always delete 
    // no longer used downloads else you'll quickly fill up your hard disk memory.  Of course, you can also 
    // store any previously downloaded file in a separate data cache for instant replay if you wanted as well.
    if (downloadingMediaFile.exists()) {
      downloadingMediaFile.delete();
    }

        FileOutputStream out = new FileOutputStream(downloadingMediaFile);   
        byte buf] = new byte[16384];
        int totalBytesRead = 0, incrementalBytesRead = 0;
        do {
        	int numread = stream.read(buf);   
            if (numread <= 0)   
                break;
            out.write(buf, 0, numread);
            totalBytesRead += numread;
            incrementalBytesRead += numread;
            totalKbRead = totalBytesRead/1000;
            
            testMediaBuffer();
           	//fireDataLoadUpdate();
        } while (validateNotInterrupted());   
       		stream.close();
        if (validateNotInterrupted()) {
         //	fireDataFullyLoaded();
        }
    }

And constantly runs the testMediaBuffer() class. Which is here:

/**
     * Test whether we need to transfer buffered data to the MediaPlayer.
     * Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
     */  
    private void  testMediaBuffer() {
      Runnable updater = new Runnable() {
          public void run() {
              if (mMediaPlayer == null) {
              	//  Only create the MediaPlayer once we have the minimum buffered data
              	if ( totalKbRead >= INTIAL_KB_BUFFER) {
              		try { 
              			//mUri=Uri.parse(path);
              			openVideo();
              		} catch (Exception e) {
              			Log.e(getClass().getName(), "Error copying buffered conent.", e);    			
              		}
              	}
              } else if ((totalKbRead - pfile) >= 4000){ 
              	//  NOTE:  The media player has stopped at the end so transfer any existing buffered data
              	//  We test for < 1second of data because the media player can stop when there is still
              	//  a few milliseconds of data left to play
              	transferBufferToMediaPlayer();
              }
          }
      };
      handler.post(updater);
    }

Until then, everything is working fine, but the transferBufferToMediaPlayer () class, which is launched when the downloaded buffer exceeds the one that was downloaded before by 4 MB, drops the sound and video at the moment the file is replaced.
And I don't understand how to get around this drop. From the commented out it is clear that there was a war. Maybe someone has some suggestions or experience in creating a video player with streaming to a folder? Here is the code for this class:

/**
     * Transfer buffered data to the MediaPlayer.
     * NOTE: Interacting with a MediaPlayer on a non-main UI thread can cause thread-lock and crashes so 
     * this method should always be called using a Handler.
     */  
    private void transferBufferToMediaPlayer() {
      try { 
      	// First determine if we need to restart the player after transferring data...e.g. perhaps the user pressed pause
      	boolean wasPlaying = mMediaPlayer.isPlaying();
      	
      	
      	// Copy the currently downloaded content to a new buffered File.  Store the old File for deleting later. 
      	File oldBufferedFile = new File(mContext.getCacheDir(),"playingMedia" + counter + ".dat");
      	File bufferedFile = new File(mContext.getCacheDir(),"playingMedia" + (counter++) + ".dat");

      	//  This may be the last buffered File so ask that it be delete on exit.  If it's already deleted, then this won't mean anything.  If you want to 
      	// keep and track fully downloaded files for later use, write caching code and please send me a copy.
      	bufferedFile.deleteOnExit();   
      	moveFile(downloadingMediaFile,bufferedFile);

      	// Pause the current player now as we are about to create and start a new one.  So far (Android v1.5),
      	// this always happens so quickly that the user never realized we've stopped the player and started a new one
      	mMediaPlayer.pause();
      	int curPosition = mMediaPlayer.getCurrentPosition();
      	//mMediaPlayer.release();
      	//mMediaPlayer=null;
      	// Create a new MediaPlayer rather than try to re-prepare the prior one.
      	
      	FileInputStream fis = new FileInputStream(bufferedFile);
     		
      	mMediaPlayer.reset();
            //mMediaPlayer = new MediaPlayer();

            /*if (mAudioSession != 0) {
                mMediaPlayer.setAudioSessionId(mAudioSession);
            } else {
                mAudioSession = mMediaPlayer.getAudioSessionId();
            }
            setListeners();*/
            pfile=bufferedFile.length()/1024;
            
            mMediaPlayer.setDataSource(fis.getFD());
            //mMediaPlayer.setSurface(new Surface (sf));
           // mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
            mMediaPlayer.prepare();
            // we don't set the target state here either, but preserve the
            // target state that was there before.
           // mCurrentState = STATE_PREPARING;
            //attachMediaController();
        	mMediaPlayer.seekTo(curPosition);
        	//mMediaPlayer.start(); 
    		//  Restart if at end of prior buffered content or mediaPlayer was previously playing.  
    		//	NOTE:  We test for < 1second of data because the media player can stop when there is still
        	//  a few milliseconds of data left to play
    		/*boolean atEndOfFile = (totalKbRead - pfile) >= 1000;
        	if (wasPlaying || atEndOfFile){
        	mMediaPlayer.start();
        	}*/

      	// Lastly delete the previously playing buffered File as it's no longer needed.
      	oldBufferedFile.delete();
      	
      }catch (Exception e) {
      	Log.e(getClass().getName(), "Error -------------------------------------------------------", e);            		
    }
    }

Answer 1

in general, I dig towards vitamio. There are many different players written on it.
I dug and realized that the month was lost in vain.
See the correct answer here How to save the cache in MediaPlayer?
Or right here https://github.com/master255/ImmortalPlayer

Answer 2

This one is ok.
en.macblurayplayer.com/features.htm